1915.] Allen, Review of the South American Sciuride. 279 
rower braincase and weaker dentition, and the total length of the skull is 
3 to 4 mm. less, with corresponding differences in all other measurements. 
The coloration in wrucumus is much darker than in either langsdorffii or 
stenbachi, the light tips to the hairs being shorter and paler, while the black 
in the tail is more intense and greatly increased in area. 
Urosciurus langsdorffii steinbachi (Allen). 
Sciurus langsdorffii steinbachti ALLEN, Bull. Amer. Mus. Nat. Hist., XX XIII, 
p. 596, Sept. 8, 1914. 
Type locality Santa Cruz de la Sierra, Bolivia. 
Geographic distribution.— Known only from the type locality. 
Description.— “ Differs from S. langsdorffiit langsdorffit in much paler 
coloration throughout, the hairs of upperparts being slightly tipped with 
pale yellow instead of heavily tipped with orange; the top of the head and 
nape slightly washed with yellow instead of orange rufous; nose and sides 
of head dull yellowish instead of deep rufous; thighs rufous instead of chest- 
nut; underparts pale yellow instead of ochraceous yellow, and tail fringed 
with a lighter shade of yellow. 
“Total length (type, collector’s measurements), 505 mm.; head and 
body, 250; tail vertebra, 255; hind foot, 55; ear, 32. Five specimens 
(including type), total length, 491 (475-505); head and body, 254 (250- 
260); tail vertebrae, 235 (225-255); hind foot, s. u., 55 (55-55). 
“Skull (type), total length, 63; zygomatic breadth, 37; interorbital 
breadth, 23; postorbital breadth, 19; breadth of braincase, 23; nasals, 
20 X 9; maxillary toothrow, 9. Five skulls (including type), total length, 
60.6 (60.2-61); zygomatic breadth, 36 (35-37); interorbital breadth, 20.6 
(20-21); postorbital breadth, 18.6 (18-19); breadth of braincase, 23.6 
(23-24); nasals, 18.3 X 7.9 (17.8-19.8 X 7.6-8); maxillary toothrow, 
9 (9-9.2).”’ — Allen, I. c. 
Specimens examined.— Bolivia: Santa Cruz de la Sierra, 5 (Carnegie 
Mus., Pittsburgh). 
Remarks.— Agrees closely in size and in general coloration with sub- 
species langsdorffii, but is readily distinguishable by the absence of the 
strong rufous color of the head present in both langsdorffii and urucumus. 
The type locality is about 300 miles southwest of Chapada, and about the 
same distance west of the type locality of wrucumus. 
